| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1515396 | Journal of Physics and Chemistry of Solids | 2016 | 5 Pages |
•Local structures around Fe3+ impurity forming various centers in Tl2MF4 investigated.•Suitable structural models for the centers presented by analyzing EPR data.•Correlation between the experimental data and theoretical values for ZFS provided.•A clear compression of the MF6 octahedron around tetragonal Fe3+ center shown.•Both ligand length and angular distortions found for low symmetry centers.
Theoretical analysis of the Fe3+ centers observed in Tl2MgF4 fluorine crystals have been carried out by means of semi-empirical approaches. The most appropriate models are proposed by matching the theoretically predicted zero-field splitting parameters (ZFSPs) with the experimental ones obtained by EPR spectroscopy. Compression on the MF6 octahedron of tetragonal (TE) center I is indicated in both Tl2MgF4 and Tl2ZnF4. A structural model for monoclinic (MO) center II and orthorhombic (OR) Fe3+ center IV in Tl2ZnF4 is proposed by assuming that the substitution of Fe3+ induces both ligand length and angular distortions.
